In this project, we explore the etiologic mechanism(s) of two important clinical problems frequently observed in the chronic alcoholic during withdrawal: (1) disturbed sleep-wake cycle, and (2) increased susceptibility to infection. Twenty-four hour measurements of body temperature, motor activity, ambulatory EEG, and urinary catecholamine excretion will be performed on acutely withdrawing alcoholics during withdrawal and 3 weeks after withdrawal. Plasma melatonin, cortisol, and ACTH will be determined at 3-hour intervals, and hand tremor will be repeatedly measured. Lying-standing norepinephrine determinations will be made twice during the initial 72 hours and once weekly for 3 weeks. Alcoholic patients and age- and sex-matched controls will be evaluated for general immunocomponents to determine the effects of long-term alcohol abuse and withdrawal from alcohol on the immune system. Patients will be evaluated at regular intervals to investigate effects of varying durations of abstinence from alcohol on selected parameters of immunocompetency.